Most computers and electronic devices have some form of USB connection, and many devices also come packaged with a USB cable. What are all these different cables for, and why does it matter which one you use?

It can be somewhat complicated to wrap your head around all this. Here’s everything you need to know about the USB standard.

The Many Types of USB Connectors

USB is supposedly universal, but there are so many different types. Why is this? As it turns out, they each serve different functions, mainly to preserve compatibility and support new devices.

Here are the most common types of USB connectors.

Type-A: The standard flat, rectangular interface that you find on one end of nearly every USB cable. Most computers have multiple USB-A ports for connecting peripherals. You’ll find them on game consoles, TVs, and other devices too. This cable only inserts in one way.

Type-B: An almost square connector, mostly used for printers and other powered devices that connect to a computer. They’re not very common these days, as most devices have moved onto a smaller connection.

Mini-USB: A smaller connector type that was standard for mobile devices before micro-USB. While not as common today, you’ll still see these on some cameras, the PlayStation 3 controller, MP3 players, and similar.

Type-C: The newest USB standard, this is a reversible cable that promises higher transfer rates and more power than previous USB types. It’s also capable of juggling multiple functions. You’ll see it on many new laptops and smartphones, including the MacBook, Pixel phones, and Nintendo Switch Pro Controller. We discuss USB-C more below.

Lightning: This isn’t a true USB standard, but is Apple’s proprietary connector for the iPhone, iPad, AirPods, and more. It’s a similar size to USB-C and comes standard on Apple devices released since September 2012. Older Apple devices use the much larger 30-pin proprietary connector.

In most cases, you’ll find USB cables have one standard type-A end and one type-B end of some sort. The type-A end powers the device, while the type-B end receives power. This is to prevent potential damage that would be caused by connecting two computers via USB-A, for example.

The Mini and Micro connectors are considered smaller forms of type-B, even though “type-B” is usually not in their name.

In general, the cables you’ll use the most, and therefore need to replace, are micro-USB, USB-C, and Lightning.

USB Speed Standards

USB connection types are only half of the story, as USB has also gone through multiple standards of varying data transfer speeds. The cable’s connector doesn’t necessarily mean it uses a certain standard.

The three main iterations of USB’s speed are:

USB 1.x was the original standard, and is ancient by modern benchmarks. You’re very unlikely to find devices using this standard nowadays.

USB 2.0 introduced many modern USB norms, including support for Mini and Micro cables, USB OTG (see below), and more. It’s the slowest speed of USB still used today. You’ll find it used on cheap flash drives, devices like mice and keyboards, and similar. Most computers also include a few USB 2.0 ports.

USB 3.x is the current standard for USB speeds. It’s much faster than USB 2.0, and thus recommended for devices like external hard drives. You can typically identify a USB 3.x port or connector by its blue coloring. Many USB 3.0 ports also have an SS symbol (which stands for Super Speed). Most new computers have at least one USB 3 port, and good-quality flash drives use this standard.

You can use a USB 2.0 device in a USB 3 port, or a USB 3 device in a USB 2.0 port, but neither setup provides the extra speed benefit.

The below chart shows what connector types are compatible with which standards. Notice that micro-USB devices that support USB 3.x have a different plug. You’ll frequently see this on external hard drives.

What Is USB-C?

USB-C is an emerging standard that has lots of promise. It’s smaller, reversible, and fast. USB-C can both receive and provide a lot more power than previous versions of USB. In fact, Apple’s MacBook line only has a single USB-C port, with the new MacBook Pros packing several-C ports.

Aside from data transfer, USB-C can also power devices, output display to a monitor, and more. Unlike USB-A, cables with USB-C connectors on both ends are standard and allow full utilization of its powers. However, USB-C to USB-A cables are also common, allowing for compatibility with older devices.

Your phone or tablet might use USB-C instead of micro-USB. Some laptops and tablets feature a USB-C port; the Nintendo Switch uses it for power too. Since USB-C hasn’t been adopted everywhere yet, you might need to buy some USB-C to USB-A adapters to ease the transition.

What Is USB On-The-Go?

USB On-The-Go (OTG) is a standard available on many Android phones that allows portable devices to act as USB hosts.

Let’s say you have an external drive, a smartphone, and a laptop. What do you do if you want to move files from the external drive to the smartphone? The most straightforward method is to move files from the external drive to the laptop, then from the laptop to the smartphone.

With USB OTG, the smartphone can actually host the external drive, thus bypassing the need for the laptop altogether. And that’s just one of the many ways to use USB OTG.

However, not all devices support OTG. If you’re not sure, check your phone’s manual or download a USB OTG checker app. Unfortunately, Apple’s mobile devices don’t offer proper support for USB OTG.

Some Advice When Buying USB Cables

If you have an older Android phone or tablet, it likely uses a micro-USB cable. Even those deep in Apple’s ecosystem or with USB-C ports on their phones need to use micro-USB, however. It’s still a common connector type for battery packs, Bluetooth speakers, and the like.

Anyone who buys a lot of gadgets will build up a collection of micro-USB cables over time, as they’re packed in with nearly every device. Since they’re generally interchangeable, you can use different cables for your various devices.

When it’s time to buy a new cable, it’s tempting to pick the cheapest option. However, most of the time, this is a bad idea. Poorly made cables can cause you all kinds of issues. These range from annoyances like slow charging and unreliable performance to major problems like breaking and even becoming a fire hazard.

While you don’t have to buy a cable from your phone’s manufacturer, you should stick to recognized brands. It’s a small difference in price, but it’s worth it.

Another important aspect is cable length. Short cables are great for portability, but that can leave you sitting on the floor next to a power outlet as it charges. Yet a cable that’s too long can be inconvenient to carry, will tangle more easily, and is potentially a tripping hazard.

Three feet is a good minimum length for a charging cable. This allows you to keep your phone in your hand while connected to a battery in your bag or pocket. They’re also usually long enough to reach from an outlet to a desk. If you often need to use your device far away from the outlet while it’s charging, a six-foot cable will usually do.

The Best USB Cables for Every Need

Need a new cable and aren’t sure what to get? Here are recommendations for every type.

If you need some micro-USB cables of varying lengths, this pack from Anker has you covered. It includes two one-foot cables, two three-foot cables, and one six-foot cable.

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Beverley Williamson

January 6, 2019 at 4:02 pm

Hi, I use Samsung Galaxy 10.1, I'm totally confused so can you help me? I want to use an external USB mic for singing/ recording but I have no idea what to get with regards to mic or lead
Any help appreciated x

MHL cables are for connecting a phone or other device to a TV. They're typically micro-USB on one end and HDMI on the other end. This lets you connect your phone to a TV without the phone having a bulky HDMI out port on it (which some older devices had).

I wouldn't call MHL a proper USB standard or connection type. It's more of an adapter cable.

Why can't I find Micro-B USB female to 3.0 USB A male adapters? Surely someone offered them at some time. But why doesn't there seem to be any currently available? Or is Micro-B USB unable to achieve 3.0 transfer rates?

See the image at the bottom of the "USB Speed Standards" section -- for micro-USB to be USB 3.0 compatible, it needs to use a different plug for the faster speeds. These are often found on external hard drives.

Hi
I've just bought the New smartphone UMI PLUS. It comes with a Type C, USB connector, but it's Bigger than other type C connectors, Its unique, and not seen on other mobile phone , i've had before. Could you tell what is the description is exactly ? Does it has a specific number etc. If I should need to replace this USB lead at some time in future ?
Please email back your comments
Thanks
Carl

From what I can find out, the UMi Plus uses a non-standard cable. If looking for a replacement, you'll need to source one that's either made by the same manufacturer, or made specifically for that phone.

First and foremost, excellent article. Very thorough. I am intrigued and would like to learn a bit more.

Now, when you say "Some USB-C devices are compatible with HDMI", what exactly do you mean? Would a special adapter be required to plug the HDMI cable into the TV/monitor while the USB-C cable plugged into the host device?

Additionally, does USB-C alone transfer video? Or is a Thunderbolt 3 with USB-C required for video transfer? I'm also a bit confused how Thunderbolt 3 and USB-C work together in a single cable.

Ben is a Deputy Editor at MakeUseOf. He holds a B.S. in Computer Information Systems from Grove City College, where he graduated Cum Laude and with Honors in his major. He enjoys helping others and is passionate about video games as a medium.